If you can't get a confirmation code or the code doesn't work, here are a few possible reasons.

Code expired. Codes stop working after 24 hours.

Code was already used. Each code can be used only once. You need to use a new code each time you copy files.

Code was replaced. If you request a code more than once, only the most recent one works. Try again and make sure you've entered the most recent code.

Confirmation email was forwarded. If the confirmation email was forwarded to another account, selecting "Get confirmation code" won't work. Sign in to the Google Account where the email was sent and try again.

Tip: To get a new code, on the "Transfer your content" page, select Resend code.